Explosion-cycle jet propeller for aircraft propulsion



J. D. STANITZ Sept. 8, 1953 EXPLOSION-CYCLE JET PROPE LLER FOR AIRCRAFT PROPULSION Filed Oct. 31, 1949 grime/WM JOHN D. STAN/7'2 Patented Sept. 8, 1953 rams-research: iiirirfidiiifitiiit AIRCRAFT PROPULSION J oh'n D? Staiiiitz, Lakwbom Ohio talisman (man ra, 194%); shamanuitst 5 claiiiis'i- (-01. 170 13 54 (Granted under This invention relates to J'etoperated' propel lens in particular to air efficient explosioncyaejet propel-ler" engine for tli'propul'sion of aircraft: N

The general object or the invention is to pro: vide such a jet driven propeller; I I H V It is also an object of the invention to provide an: explosioii oycle' jet propeller engine in which the" combustion chamber is" located within the hub o'f the pro eller:

It is a further object of the invention to' pro v-ide an explosion-cycle jet propeller engine which; by reason of the location of the combus tionchamber within" the hub of the propeller,- operates under higher explosion pressures" and withincreased efficiency resulting therefrom.

It is an additional object of the invention to provide an explosion cycle jet propeller which is of relatively low cost in manufacture whereby the primary application may'beto light, privately'owned aircraft.

Other objectives will be apparent from-thefol: lowing description and drawin gsherew-ith sub'-' mitted, which are merely illustrative of a pre ferred'embodiment of the'invention andar'eriot' otherwise limitative thereto.

Prior .art jet-driven propellers are of twogen eral types, viz, the-steady flow type and the eX*- plosion-cyclejet type in which-thepropeller is actuated by jets located in the tipsof the pro? peller blades. Considering the explosion-cycletype (that which" concerns this invention); the prior art generally consists of locatingthecombustion chamber inthe propeller blades and e'm"--- ploys some valve mechanismnear ther'oot 'of the propeller blade toblowing back into the propeller hub through-the-ram intake; In-general; the jet nozzle sof this type are open to the atmosphere? propeller- When thecharge is exploded in the blades the gases rushoutthrough thenozzles which are located at the tips of the such away that the jet reaction-turns-the-pr0- peller which propels the plane.

One disadvantage of th s old type ofexplosion: cyclejet propeller results from the fact that large quantities-of air must be handled in order to-pro= vide sufiicient jet reaction to do large quantitiesof air require the propeller bladesthat the explosion cyclelpea kpressures are low (the gases escape through-the nozzlesbefore the pressure can be built up) andtherefore the 'cycle'eflici'eficyislowi I,

Theapplican't overcomes thisdisadif'ahtag'" by blades" in useful-work; The

large jet nozzleareas; in'fact, require such largejet'nozzle areas 1 in relation tothe combustion chamber volume in are 35, 131 s; eta

sec. 266) prevent the explosion'from and out rear of? V Y 2 constructing and" g hiis iiplosion oy et'pfopeller engineas show ii ih'the aeaompany: ing' drawing wh'er'ein r Fig: 1- is a partial mfi'gitud iiar seetionalere:- vatibnal View throng-h the propel-lei showing the structural'bearingsupport? aid Figr2 is-afrontelevation As=shbwn in Fi'gfl thepropeuermay two or moretubIi-la'r blades fli arena; tip are provided jet nozzles" r2: integral with" streamlined h'u-b F4} w with an" end plate It". Shaft I8 is firmly attached to plate re at the center thereof an" t is rotatably mounted in bearings 2 0 which" are in t'urrr supported by hearing biocle 22;: Atits front-end bearihg ignition= ring 24* which by brush thereof;

isdi'i1'1ed longitudinally and axially as at P9 provide a passage for fuel from pump 2| Tlfi"s pumpfis connected to a fuel reservbir through manual" valve (FL-as shown? passage HT' terminates ma noz'zlefi" whieli e tends into combustion' c'hamber" 30- and irfi metered" ffiE1"f1'0m"l'/h" pump into said coinbu tionch'amberf- Thefreduen'cy' or rue-1" injection froih the pinnp to the colfibustion chamber 31F is controlled*- by any conventional" means slich far" example;- as the" cam actuated injection p nip shown? the patent t'dWilliQlln" ick; N" 2,446-;785;dasted* 10 August 1948. The forward end of hlib=Misrfiioiildd'Withfaii' missio n ofair 'therethrougliz' Iriducervanes' 35 may be attachedto valvejseat'plate" 3G;- extend ingtherefron into: inlet 3-2; to impart a rotation? to'the incoming air at the valve seat plate 3 l' t f" Y? parted-em ing th' I I inwa ifdl or are r bertthe pol tis' ex valye dise for iiii o of floatng 'disc' 'valv '42; mounted on pin '44, which 1y i lve sea-t platesil and '3'8. 'TheWu'tional operati9mofdisc waived? will'ibe' described here ina f r: 1 r

The tubular propeller blades III are provided with scoops 46 and partition plate 41 which assist in gathering and guiding the combusted gases out through jet nozzles I2. Partition plates 41 also strengthen propeller blades enabling them to hold their shapes.

In the operation of the jet engine of this invention air enters combustion chamber 30 in the propeller hub through inlet port 32 and around floating disc valve 42. This air is mixed with fuel injected through nozzle 23. The mixture is exploded at relatively high pressure due to the fact that floating disc valve 42 operates as a check valve in moving plate 34. The exploded mixture expands through the propeller blades and out through jet nozzles l2 which are located at the tips of the propeller blades in such a way that the jet reaction imparts rapid rotation to the propeller which in turn propels the plane. After the explosion and blowdown the combustion chamber is purged by the inertia of the gas column flowing through the blades during blowdown, by the centrifugal pumping action of the rotating blades, and by the ram air at the engine intake. When the combustion chamber pressure becomes low enough disc valve 42 moves off of its seat on valve seat plate 34 thereby admitting air through the slotted (or perforated) valve seat plate 34 andthrough ports 40 of plate 38 in the areas thereof beyond the periphery of the valve disc, when moved against plate 38. When the explosion occurs, the disc valve closes preventing blowback of the charge through the intake and thereby increasing the explosion pressure and forcing the gases out through the blade jets. In both the open and closed positions the floating disc valve rests on slotted or perforated seats which support the said disc valve. This disc valve is sufliciently light to respond quickly to the pressure differentials so that the charging time does not occupy too large a percentage of the total cycle time.

During the flow of the air into the combustion chamber or thereafter, the fuel is injected through a suitable nozzle 23 and ignited by a continuous spark as previously indicated. The cyclic frequency of the engine is controlled by the frequency of fuel injection and may be increased up to the maximum value possible with sufficient time for charging, combustion and blowdown. The power output of the engine is controlled by the frequency of fuel injection and V injected during the cycle.

the quantity of fuel The combustion chamber in the propeller hub is made sufficiently large relative to' the jet nozzle area to enable high explosion pressures to be developed therein. The combustion chamber must be sufliciently large so that the gases escaping through the nozzles during combustion do not greatly reduce the peak pressures resulting from combustion.

After combustion the gases flow through the tubular or hollow propeller blades and out and through the jet nozzles. The nozzle area is selected to provide the required jet power and may be any size up to and including the crosssectional area of the propeller blade. While propeller blades are twisted in actual practice to conform to aerodynamic requirements, in the drawings the blades are shown straight for ease of illustration.

The advantages of a jet propeller engine constructed in accordance with this invention are: 1. Improved efficiency because of the higher to a seat on valve seat explosion pressures made possible by combustion in the propeller hub.

2. A simplified method of controlling engine frequency, 1. e. controlled fuel injection frequency.

3. A simplified method of controlling engine power, i. e. controlled fuel injection frequency and fuel quantity per cycle.

While the applicant has disclosed herein a specific form of a jet propeller engine, he does not desire to be strictly limited thereto as one skilled in the art could vary the structure shown without departing from the spirit or scope of the invention as defined. For instance the check valve in the inlet could be varied structurally and the rotation of the propeller hub could be used to enable the air to flow more easily into the combustion chamber than out. Such variations are included in the scope of the invention to the extent as defined by the herewith appended claims.

The invention factured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

What is claimed is:

1. In combination with supporting aircraft structure, a jet driven propeller provided with hollow blades, a hub for said propeller connected 1 to the blades thereof, a shaft, provided with an axially extending conduit, centrally connected to one end of said hub and mounted for rotation with respect to the supporting aircraft structure, a combustion chamber positioned within said hub, said combustion chamber being in communication with the interior of the blades of said propeller, an air inlet port in the other end of said hub in communication with said combustion chamber for introducing combustion air into said chamber, check valve means positioned between said inlet port and said combustion chamber effective on gas explosion for preventing backflow of gases from said chamber into said air inlet port at the instant of gas explosion, fuel iet nozzl means mounted on the end of said shaft within said combustion chamber and in communication with said conduit therein, a reservoir mounted on said aircraft structure, pump means mounted on the other end of said shaft for supplying quantity to form an explosive mixture with the v inlet air in said combustion chamber, means extending into said combustion chamber for igniting said explosive mixture as it is formed and jet nozzl means positioned at the tips of said pro peller blades, in communication with the interior of said blades, for imparting rotation to said propeller blades by the jet reaction of the combustion gases passing therethrough from said combus'tion chamber.

2; In combination with supporting aircraft structure, a jet driven propeller provided with hollow blades, a hub for said propeller connected to the blades thereof, a shaft, provided with an axially extending conduit, centrally connected to one end of said hub and mounted for rotation with respect to the supporting aircraft structure,

a combustion chamber positioned within said hub, said combustion chamber being in com munication with the interior of the blades of said prTapeller, an air inlet port inthe other end of described herein may be manuinlet port thereinto, two spaced inner and outer perforated valve seats positioned between said inlet port and combustion chamber, a disc check valve slidably mounted between said valve seats on a pin sup ported by said valve seats centrally thereof, said disc check valve having a diameter sufficient to cover the apertures of the outer valve seat but insufficient to cover the inner valve seat apertures permitting the flow of inlet air therearound into said combustion chamber but on gas explosion preventing backfiow of gases from said chamber into said air inlet port, a fuel nozzle mounted on the end of said shaft within said combustion chamber and in communication with said conduit therein, a reservoir mounted on said aircraft structure, pump means mounted on the other end of said shaft for supplying fuel from said reservoir to said conduit and said fuel nozzle at a predetermined frequency and quantity to form an explosive mixture with the inlet air in said combustion chamber, a plurality of electrical spark plugs the spark gaps of which extend into said combustion chamber, an electrical energy distributing ring having a continuous brush contact with the spark circuit of said spark plugs whereby said spark gaps constantly discharge to ignite said explosive mixture as it is formed in said combustion chamber, and jet nozzles posit-ioned at the tips of said propeller blades in communication with the interior of said blades for imparting rotation to said propeller blades by the jet reaction of the combustion gases passing therethrough from said combustion chamber.

3. In the apparatus as defined in claim 2, a plurality of spaced vanes attached to the first of said perforate valve seats and extending into said to impart a rotation to the incoming air.

4. In combination with supporting aircraft structure, a jet driven propeller provided with hollow blades, a hub for said propeller connected to the blades thereof, a shaft provided with an axially entending conduit connected to one end of said hub and mounted for rotation with respect to th supporting aircraft structure, a combustion chamber within said hub and in communication with the interior spaces of said blades, an air inlet port in the other end of said hub in communication with said combustion chamber for introducing combustion air into said chamber, a check valv positioned between said 6 inlet port and combustion chamber effective on gas explosion for preventing backflow of gases from said chamber into said air inlet port, fuel jet nozzle means mounted in said combustion chamber wall in communication with said shaft conduit, means connected to said conduit for supplying fuel to said fuel nozzle through said conduit from a source of fuel supply to form an explosive mixture with chamber air, means extendmunication with the blade interior spaces for imparting rotation to said blades.

5. In combination with supporting aircraft structure, a jet driven propeller provided with hollow blades, a hub for said propeller connected to the blades thereof, a shaft connected to one side of said hub and mounted for rotation with respect to the supporting aircraft structure, a combustion chamber within said hub and in communication with the interior spaces of said blades, a fuel inlet within said chamber, means including a pump and connecting conduit for supplying fuel intermittently to said inlet and chamber, an air inlet port in the other end of said hub in communication with said chamber, a check valve positioned between said port and chamber for preventing backfiow of gases from said chamber into said port while permitting inflow of air from the port to the chamber, and means including a continuous electric arcing device positioned in said chamber for igniting an explosive mixture of said fuel and air, said check valve being actuated to close said inlet port only by the explosive expansion of said ignited gases.

JOHN D. STANITZ.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,397,357 Kundig Mar. 26, 1946 2,446,785 Quick Aug. 10, 1948 2,490,623 Elsby Dec. 6, 1949 FOREIGN PATENTS Number Country Date 768,623 France May 22, 1934 27,087 Great Britain of 1910 

